Riera of Calders Nature · Calders, Moianès, Barcelona The river of Calders rises in Monistrol de Calders, on the north-western side of the village, from the union of two streams, the Golarda and that of Sant Joan, at a point known as els Mesclants. It runs for about 10 kilometres, with a catchment of 160 km², crossing Monistrol de Calders and Calders, in the Moianès, and Navarcles, in the Bages, where it flows into the Llobregat near the Fàbrica del Molí d'en Serra. It receives tributaries such as the torrents de les Fonts, la Querosa and Bellveí, as well as the riera de Navarcles near its mouth. It is notable for its numerous meanders and for the calderes, rounded erosion formations carved by the water in the gorges along its course. Photo: Gustau Erill i Pinyot (CC BY-SA 3.0) What to see and do in Calders